Perturbative QCD study of $B\to D^{(\ast )}$ decays

Abstract

We compute various form factors involved in $B\to D^{(\ast )}$ transitions based on the perturbative QCD formalism, which includes Sudakov effects from the resummation of large radiative corrections in a heavy-light system. A two-parameter model wave function for $D^{(\ast )}$ mesons is fixed using data of the nonleptonic decays $B\to D^{(\ast )}\pi$, from which the ratio of the decay constants $f_{D^{\ast }}/f_D=0.92$ is obtained. We then derive the spectrum of the semileptonic decay $B\to D^{\ast }\ell \nu$ in the fast recoil region of the $D^{\ast }$ meson, and extract the CKM matrix element $|V_{cb}|=0.043\times (0.12\mathrm{GeV}/f_B)\times (0.14\mathrm{GeV}/f_D)$, $f_B$ and $f_D$ being the $B$ and $D$ meson decay constants, respectively. Here we adopt the convention with the pion decay constant $f_{\pi }=93$ MeV. With these outcomes, we evaluate the decay rate of $B\to D{D}_s$, and estimate the ratio $f_{D_s}/f_D=0.98$ from data. Contributions of internal $W$-emission and $W$-exchange diagrams are briefly discussed.

19 pages in Latex, 7 figures in ps

References in corpus (11)

• Heavy Quark Symmetry
• Extraction of $V_{ub}$ from the Decay $B\to \pi l\nu$
• Model-Independent Extraction of |V_{cb}| Using Dispersion Relations
• Exclusive Hadronic B Decays to Charm and Charmonium Final States
• Measurement of the B -> D^* l nu Branching Fractions and |Vcb|
• Applicability of Perturbative QCD to $B\to D$ Decays
• $|V_{cb}|$ from OPE Sum Rules for Heavy Flavor Transitions
• Higher Order $1/m$ Corrections at Zero Recoil
• A Lattice Computation of the Decay Constants of $B$ and $D$ Mesons
• The Subleading Isgur-Wise Form Factor ${\xi }_3(v\cdot v^{\prime })$ and its Implications for the Decays $\bar{B}\to D^{(\ast )}\ell \bar{\nu }$
• Isgur-Wise Function and $V_{cb}$ from Bethe-Salpeter Equations

Cited by in corpus (23)

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• Factorization theorems, effective field theory, and nonleptonic heavy meson decays
• $B\to D^{(\ast )}$ form factors in perturbative QCD
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• Polarizations in B -> VV decays
• Nonfactorizable contributions to $B\to D^{(\ast )}M$ decays
• Perturbative QCD analysis of $B\to \varphi K$ decays and Power counting
• Nonfactorizable soft gluons in nonleptonic heavy meson decays
• Final state interaction and $B\to KK$ decays in perturbative QCD
• Λ_b \to ΛJ/ψdecay in perturbative QCD
• The CKM suppressed $B(B_s)\to {\bar{D}}_{(s)}P,{\bar{D}}_{(s)}V,{\bar{D}}_{(s)}^{\ast }P,{\bar{D}}_{(s)}^{\ast }V$ decays in perturbative QCD approach
• $B\to \varphi K$ and $B\to \varphi X_s$ in the Heavy Quark Limit
• The quasi-two-body decays $B_{(s)}\to (D_{(s)},{\bar{D}}_{(s)})\rho \to (D_{(s)},{\bar{D}}_{(s)})\pi \pi$ in the perturbative QCD factorization approach
• The $B_c\to D^{(\ast )}T$ decays in perturbative QCD approach
• The $B(B_s)\to D_{(s)}({\bar{D}}_{(s)})T$ and $D_{(s)}^{\ast }({\bar{D}}_{(s)}^{\ast })T$ decays in perturbative QCD approach
• Quasi-two-body decays $B\to D{K}^{\ast }(892)\to DK\pi$ in the perturbative QCD approach
• Internal W-emmission and W-exchange Contributions to {\bf B}\to {{\bf D}^{(*)} Decays
• Perturbative approach to the penguin-induced $B\to \pi \varphi$
• Resummation with Wilson lines off the light cone
• Electroweak Model Independent Tests for SU(3) Symmetry in Hadronic B Decays
• The role of $D_{(s)}^{\ast }$ and their contributions in $B_{(s)}\to D_{(s)}h{h}^{\prime }$ decays
• Perturbative QCD analysis of $B(B\to Xl\bar{\nu })$, charm yield $<n_c>$ in B decay, and $\tau ({\Lambda }_b)/\tau (B_d)$
• PQCD approach to exclusive B decays